Changing scroll and view state in onpopstate shouldn't overwrite back/forward state restore

third_party/WebKit/Source/core/loader/DocumentLoader.cpp

Index: third_party/WebKit/Source/core/loader/DocumentLoader.cpp
diff --git a/third_party/WebKit/Source/core/loader/DocumentLoader.cpp b/third_party/WebKit/Source/core/loader/DocumentLoader.cpp
index 0287ed28e3c3169d961a0a8383ab7858301bb494..0b9012cb8ec3d90ecc82fc50600948c1f494a35c 100644
--- a/third_party/WebKit/Source/core/loader/DocumentLoader.cpp
+++ b/third_party/WebKit/Source/core/loader/DocumentLoader.cpp
@@ -354,12 +354,16 @@ void DocumentLoader::SetHistoryItemStateForCommit(
        !EqualIgnoringFragmentIdentifier(old_item->Url(), history_item_->Url())))
     return;
   history_item_->SetDocumentSequenceNumber(old_item->DocumentSequenceNumber());
-  history_item_->SetScrollOffset(old_item->GetScrollOffset());
-  history_item_->SetDidSaveScrollOrScaleState(
-      old_item->DidSaveScrollOrScaleState());
-  history_item_->SetVisualViewportScrollOffset(
-      old_item->VisualViewportScrollOffset());
-  history_item_->SetPageScaleFactor(old_item->PageScaleFactor());
+
+  if (HistoryItem::ScrollAndViewState* scroll_and_scale_state =

[majidvp, 2017/06/26 16:19:26]

s/scroll_and_scale_state/scroll_and_view_state/

Instead of copying each member individually this should just copy the old
object, either via a copy constructor or just use of|CopyScrollAndViewState()|.

[Nate Chapin, 2017/07/11 22:17:59]

Done.

+          old_item->GetScrollAndViewState()) {
+    history_item_->SetScrollOffset(scroll_and_scale_state->scroll_offset_);
+    history_item_->SetVisualViewportScrollOffset(
+        scroll_and_scale_state->visual_viewport_scroll_offset_);
+    history_item_->SetPageScaleFactor(
+        scroll_and_scale_state->page_scale_factor_);
+  }
+
   history_item_->SetScrollRestorationType(old_item->ScrollRestorationType());
 
   // The item sequence number determines whether items are "the same", such